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iEQ45 motors humming

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#1 Midnight Dan

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Posted 22 April 2011 - 10:53 AM

I bought an iOptron iEQ45 at NEAF. I've noticed some odd behavior with the motors and I wondered if other iEQ45 owners could let me know how this compares to their mounts.

I have not had a chance to really use it due to clouds, but I set it up in my house and have been learning how to use it. When I turn the mount on and set up the location and time, the motors are silent. If I use one of the arrow buttons, I can hear the appropriate motor run, then when I release it the motor seems to stop, but still hums. I'm not sure if the hum means it is still running very slowly or if it is just humming but not moving. If I hit the same button again and release, the motor stops and is silent. It generally repeats this pattern of hum/silent after each time I use the button, but it is not always consistent. For example, some times it might hum two times in a row. This effect occurs with either motor. Note that it appears that the mount is stopped because the RA indication on the handset changes slowly.

After setting up the mount indoors, I told it to goto the location of the sun, which it did. I could hear the RA motor running in its tracking mode. The RA indication on the handset was not changing so it appears to be tracking correctly. I then told it to go back to the zero position. It did so, and afterwards, both motors were humming. I've left it there for about 10 minutes now and they are still humming. Again, the mount appears to not be moving because the RA display is slowly changing.

Other than this hum, the mount seems to be working fine ... at least as much as I can determine indoors. I have reported this to iOptron and they have not heard of the issue and will look into it. But I was wondering if other owners could try this on your mount and let me know if you are experiencing this or not.

-Dan

#2 PHampson

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Posted 22 April 2011 - 11:24 AM

Mine does it too, but it is a very low level hum. As it hasn't seemed to cause any problem, I just ignored it. I'll be interested in what iOptron has to say about, though. Thanks for raising the issue with them.


Paul

#3 LouP

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Posted 22 April 2011 - 01:15 PM

I think it's tracking something guys. I noticed that on mine also and to me it sounds like it's tracking an oblect. Hit the "stop tracking" and see if it stops.

LouP

#4 Midnight Dan

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Posted 22 April 2011 - 01:46 PM

The stop button has no effect. The only way I can get it to stop is to use on of the arrow buttons for the motor that's humming. And it doesn't seem to be tracking because the RA display on the handset is changing every second or so as if the sky is moving past the mount's position. When the mount is tracking, the RA display does not change because it is moving along with the sky.

The sound reminds me of an electric train set I had as a kid. There was a lever on a power supply that increased the voltage to adjust the train speed. As you increased the voltage from zero, the train would start to make a humming sound before it got to the point where there was actually enough voltage to get things moving. That's what this sounds like. I know these motors are nothing like what you'd find on an electric train set, but nonetheless, that's the sound.

-Dan

#5 Nick Rose

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Posted 22 April 2011 - 02:01 PM

I don't have the iEQ45 but I do have the GOTO Nova kit and the motors make the same noise.

#6 Midnight Dan

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Posted 22 April 2011 - 03:32 PM

I got a response iOptron (I'm very impressed with their interest and response time!) and they said the units they have do the same thing. They said that it is normal for the system and, as long as everything else works, it should not affect the operation of the unit.

-Dan

#7 SweenyTodd

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Posted 22 April 2011 - 03:45 PM

Thank you much Dan for chasing this down...mine does the same thing and I was starting to wonder about it. I have been running off a small 12v battery and do not see any appreciable current drain due to the noise. It bugs me that it is so inconsistent...sometimes I can tap a slew button and it will stop.

#8 seisner01

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Posted 22 April 2011 - 09:17 PM

I happen to own the "baby brother" of the I45 - the SmartStar PR GEM... and I also have the same problem, as does just about everyone else. Apparently this is a characteristic of ALL of their EQ drive units (according to their tech support). Mine also just blew a circuit board. Maybe a replacement will not buzz as much.

#9 Midnight Dan

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Posted 22 April 2011 - 10:09 PM

Seems like others are having the same problem when using the GoTo Nova system, even when it's not an iEQ45. So I doubt the issue is in the circuit board.

Even though they say it's "normal", still doesn't seem right to me. I'm guessing there's some little glitch in the GoTo Nova firmware. Like SweenyTodd, I can tap a slew button and get it to stop. I guess I won't lose any sleep over it, but I'm hoping the next firmware update takes care of it.

-Dan

#10 billn

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Posted 23 April 2011 - 09:13 AM

Dan, interesting observation. I just checked mine and here is what I noticed just now.

1. Turned the mount on and it was immediately in tracking mode (CEL) with the pulse sound coming from the motors. The R.A. display static. The previous night I had imaged and had parked the mount prior to powering off. Pressing Stop on the hand controller stopped tracking. No motor hum.

2. Turned the mount off and then back on and the mount motors were silent and not tracking. Pressing stop enabled tracking and the "oscillation" sound from the motors is heard.

3. Power cycled the mount again and tracking was off. Started and then stopped the mount tracking with the stop button but this time when the mount was stopped the motor humming is heard. Cycled the stop button a few times and the motor sound changed a bit until after a fourth stop the motor was silent. Seems random.

-Bill

#11 Midnight Dan

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Posted 23 April 2011 - 09:53 AM

Interesting. Seems like everyone has this problem to one degree or another. Maybe if everyone lets iOptron know about their experiences, they might be more motivated to correct it instead of just saying it's "normal"?

Seems to me the motors are getting fed some small amount of power, but are not moving. While I don't see that as any kind of immediate problem, I can't imagine that it's particularly good for the motors long term.

-Dan

#12 Don Allen

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Posted 23 April 2011 - 03:27 PM

We have a few "new" CN'ers posting on this thread. Welcome and we look forward to your future contributions.

#13 SweenyTodd

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Posted 23 April 2011 - 03:34 PM

I bought the mount because of its light weight for use as a portable mount. The last thing I need is for it to murphy me at a star party hundreds of miles from home. I stopped the mount and let it hum for two days...so far no smoke. I have not put a amp meter in the circuit to see how much the humming is drawing. I just don't feel good about this, but see no problem so far. Good mount otherwise.

#14 MallBoy

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Posted 24 April 2011 - 01:03 AM

I think mine is doing the same thing, but not sure. Is this a very low sort of buzzing like an insect or winding a watch sound?

#15 wasyoungonce

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Posted 24 April 2011 - 04:31 AM

I had the original system Gotostar (GTS). It used to occasionally "hum" as well.

This is not a problem, its just a servo loop continuing to hunt for its correct position. I heard the same noises when working on Aircraft instrument servo systems.

#16 SweenyTodd

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Posted 24 April 2011 - 04:49 PM

Thank you, that does ring true. I recall messing with servo controlled systems in the past that would softly hum at times. I forgot these are not steppers. This is likely a non-issue.

#17 billn

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Posted 25 April 2011 - 07:47 AM

I assume the system needs to know the location of both servo motor and worm gear position as there is an encoder disc on the end of the gear shaft. If the controller has both known positions then maybe it doesn't need to hunt and therefore the motor is quiet. I have Servos on my CI-700 (Gemini) and they are quiet until tracking, these encoders are integral to the motor.

-Bill






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